Thanks for the great reply Vallex!
Balancing things is always tricky, and I certainly don't think it's perfect here. After the initial setup and tuning period, I've mostly taken a philosophy of only fixing what's broken. I feel like a lot of players (and probably server admins too) are too quick to decide that something needs changing based on a very specific situation. It's also very difficult to see the secondary effects of a given change, even when you're looking for them (which most people don't). It's why you even see terrible, terrible changes made on live games staffed with hundreds of employees.
EQ allows for huge variances in effectiveness. The difference between optimal and middling can be massive. A group composition is MUCH better than a bad group. A well geared/AA's player can be MUCH better. A good player can be MUCH better. Of course, some of it depends on the class and encounter, but still, when you stack those changes together, the difference between average and optimal can be HUGE. And if you balance everything to the average, it's going to be completely trivial for the optimal.
Of course, I don't think everything should be balanced for the optimal, but I think it's ok that the very top-end content is. For example, plenty of people have killed Fennin, only a handful have killed Quarm, and those that did either went to some pretty exceptional lengths or used more people. That seems pretty much in the spirit of EQ to me.
raid targets are too strong for a group e.g. level 50 group equipped with best in slot 50 gear can't take down that expansions raid targets
Ok so you can kill Naggy/Vox easily at 50. Sky? probably not. (Fear/Hate are post-upgrade, so they're Velious level, and you can take them with a Velious level group).
You can kill Trak with a Kunark level/gear group. (VP is upgraded version, so GoD era)
AoW would be rough, but you could likely do most of ToV with a Velious group (note that Vulak is the upgraded version).
Not sure about Luclin tbh, but I would guess that you could get through the vast majority of it with an optimal group.
(Also consider that on Live, the hardest piece of content per expansion was usually only doable by a tiny number of uberguilds before the next expansion released, and even then, it was only after months of gearing up, failed attempts, and finding exploits to leverage.)
So no, it may not even be possible to do every fight here with only what was available at the time, but the problem is that practically no one plays that way unless it's forced. If you made it "reasonable" to do so, it would be utterly trivial for optimal and/or overleveled/geared groups. Trying to balance around that would would literally mean rebalancing the entire game, and it probably wouldn't feel very much like EQ afterwards.
On your specific situation (assuming that I checked the right toons, and apologies if not):
If you're tying to clear VT without taking advantage of anything beyond Luclin (including lv60 and the accompanying aa's), it SHOULD be as hard as Time and probably should require pretty close to optimal group comp, gear, aa's, and execution. While you are 65, there are a lot of suboptimal bits too. Your tank has a reasonable number of aa's, assuming that they're spent well, but he is an SK. SK's can tank well enough, but if you're pushing the edge of what's do-able, then every sub-optimal piece adds up.
The rest of your group still needs to catch up on AAs, so even though you're 65, you're still missing a lot of effectiveness that would come with an optimized luclin-era group. 150ish aa pretty well covers things in that era I think, but your average is well below 100. And two of your toons have basically no aa at all. I would probably take a lv60-150aa cleric over a 65/0 cleric. Hit/miss rate based on level may help the tank/dps, but your support classes don't gain as much benefit from the levels unless it's unlocking some crucial new spell.
The rest of the group isn't exactly optimal either. Unless you're charming with the chanter, he's not bringing much to the table (not even sure that's possible in VT) as long as you also have a shammy. You clearly need one slower on mobs that are slowable, but even the shammy ends up as dead weight on unslowables (puma might make enough of a difference to make up for a missing dps, not sure without parsing). I assume the wiz falls pretty far behind the melee dps. I assume the ranger does ok, but I haven't really parsed one, and your monk has no aa's.
BUT, the point isn't to say that everything always has to be optimal, because even with all that, you got this beastly, unslowable, endgame mob to 40%. Once your group maxes out their Luclin AA, he should be a dead mob. With a different group composition, he'd be dead already. Just consider what a sub-optimal comp causes you to give up before assuming that things are impossible. If your characters were an ideal mix with max luclin aa's, your DPS would probably triple while taking far less damage (and you'd still have a few hundred useful aa to get for PoP left to go).
So maybe a better description would be "95% reasonably-groupable, 5% optimally-groupable"? (Shit, it's probably even "70% entirely-non-reasonably-groupable" lol). Doesn't roll off the tongue very well though :)